You have been wrongly informed by some miscreant abut this automatic divorce.
There is no such rule or law that when a husband and wife live separately,for a specific time or beyond that shall get automatic divorce.
This type of your innocence is the reason that you have been made to suffer so much by your husband and and in laws.
You have full rights to live in your matrimonial house so long you are not divorced or your marriage has been dissolved by a decree of divorce in the court of law.
You can enter in to your matrimonial house with the help of police support.
Your in laws cannot refuse you to enter their house. If they do so, you can file a domestic violence case against them for protection, residential rights and return of property.
You may take the help of a local lawyer to solve all such further issues legally.